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61.
A method for rapid calculation of the multiply-scattered solar induced radiation field in the troposphere and stratosphere is presented. The method is described in sufficient detail so that the mathematical model can be incorporated in a straightforward manner into photochemical models of the troposphere and stratosphere. Results are described which show that multiple scattering and ground albedo can result in large amplifications of the radiation field in the photochemically active region 240–1000 nm. 相似文献
62.
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64.
Knowledge of the driving forces behind indigenous participation in the market is essential for practitioners intending to integrate conservation and development policies in indigenous territories. Nevertheless, empirical research on the determinants of market integration among indigenous peoples is still scarce. This article uses household survey data and multivariate techniques to examine the drivers of market integration among indigenous groups in the Ecuadorian Amazon. We use multiple measures of market integration, including the sale of crops, timber, and wildlife; the use of credit; and participation in wage labor. The results show that the way in which indigenous peoples integrate into the market depends on their endowments of human, financial, and physical capital. More educated households are able to engage in commercial agriculture and nonagricultural wage work, whereas uneducated poor households in communities in conflict with outsiders are pushed to engage in poorly paid agricultural wage work and (often illegal) timber operations. 相似文献
65.
Hilmar von Eynatten Thomas Voigt Angela Meier Hans-Joachim Franzke Reinhard Gaupp 《International Journal of Earth Sciences》2008,97(6):1315-1330
The Harz Mountains and the adjacent Subhercynian Cretaceous Basin figure as the most prominent surface representative for
Late Cretaceous inversion structures in Central Europe. Facies, depositional architecture and provenance of the basin fill
reflect mechanisms and timing of the exhumation of the Harz. From Hauterivian to Early Santonian there is no evidence for
detrital input from the nearby Harz area. Sediments are mature quartzarenites derived from Paleozoic basement rocks and/or
recycled Permian to Mesozoic sedimentary rocks. This situation changed drastically in Middle to Late Santonian when freshly
exhumed and eroded Mesozoic sedimentary cover rocks of the Harz were delivered into the basin. Feldspar and lithoclasts reflect
erosion of Triassic and, in places, Jurassic to Turonian strata. Apatite and garnet in heavy mineral spectra are derived from
largely unweathered Lower Triassic Buntsandstein as indicated by apatite and garnet chemistry. In Early Campanian, Paleozoic
lithoclasts indicate erosion cutting down into the basement of the Harz. Simultaneous strong decrease of feldspar, garnet
and apatite suggest an almost complete removal of the 2–3 km thick Mesozoic cover of the Harz within only 2–4 Myr. This translates
into an exhumation rate of approximately 1 mm/a consistent with apatite fission track data from granitoid rocks of the Harz
Mountains. 相似文献
66.
Claus Doll Christian Trinks Norbert Sedlacek Verena Pelikan Tina Comes Frank Schultmann 《Natural Hazards》2014,72(1):63-85
The assessment of the current impacts of extreme weather conditions on transport systems reveals high costs in specific locations. Prominent examples for Europe are the economic consequences of the harsh winter periods 2009/2010 and 2010/2011 and the floods in Austria, Eastern Europe, Germany and the United Kingdom in 2005 and 2007. Departing from the EC-funded project WEATHER, this paper delves into the subject of adaptation strategies by revisiting the project’s general findings on adaptation strategies and by adding two specific cases: (1) advanced winter maintenance on roads in southwest Germany and (2) technical and organizational measures in Alpine rail transport. For these two cases, feasible adaptation strategies are elaborated and their potential is discussed in light of damage cost forecasts up to 2050. For the road sector, we find a high potential to mitigate weather-related costs, although damages here are expected to decline. In contrast, rail systems face strongly increasing damages and the mitigation options offered by improved information and communication systems seem to be largely exploited. Consequently, it is easier to justify expensive adaptation measures for high-cost rail infrastructures than for road transport. A generic analysis of 14 damage cases worldwide, however, revealed that generally awareness raising, cooperation and communication strategies are sufficient to mitigate the most severe damages by natural disasters. 相似文献
67.
Based on the spherical cavity expansion (SCE) problem, Cudmani and Osinov (Can Geotech J 38:622–638, 2001), Osinov and Cudmani
(Int J Numer Anal Method Geomech 25:473–495, 2001) developed a semi-empirical method of interpretation of CPT for coarse-grained
soils (sand, gravel) using a hypoplastic constitutive model. Using a material-independent shape factor, the cone penetration
resistance was related to the limit pressure required to expand a spherical cavity. The shape factor was observed to be a
function of the soil state only, in particular the pressure-dependent relative density. This paper presents an analogous interpretation
technique for CPT in fine-grained soils using the shape factor concept, Cavity Expansion approach, and a hypoplastic constitutive
model. Relations for the shape factor and the limit pressure have been proposed based on the parameters affecting these quantities.
A validation of the proposed interpretation technique with experimental results has also been performed. 相似文献
68.
David L. Meier 《Astrophysics and Space Science》2005,300(1-3):55-65
In this paper I propose that the inner part of a black hole accretion inflow (< 100 rg) may enter a magnetically dominated, magnetosphere-like phase in which the strong, well-ordered fields play a more important
role than weak, turbulent fields. In the low/hard state this flow is interior to the standard ADAF usually invoked to explain
the observed hot, optically thin emission. Preliminary solutions for these new MDAFs are presented.
Time-dependent X-ray and radio observations give considerable insight into these processes, and a new interpretation of the
X-ray power spectrum (as arising from many disk radii) may be in order. While an evaporative ADAF model explains the noise
power above 0.01 Hz, an inner MDAF is needed to explain the high-frequency cutoff near 1 Hz, the presence of a QPO, and the
production of a jet. The MDAF scenario also is consistent with the phenomonological models presented at this meeting by several
authors. 相似文献
69.
Polycyclic aromatic hydrocarbons (PAH) and alkylphenols (AP) that are present in routine discharges of produced water (PW) from the offshore industry continue to cause concern. The suitability of biological methods and chemical based passive samplers to determine exposure to these compounds was tested by deploying them around an oil installation and at reference locations in the North Sea. PAH and AP were analysed either as parent compounds in passive samplers and mussel tissue or as metabolites in fish bile. Generally the pattern of exposure relative to proximity to the discharge was represented by mussels, SPMDs and fish for PAH. Fish and SPMDs showed good correlation for PAH accumulations, whereas some differences were apparent between mussels and SPMDs. POCIS was the only technique tested that could accurately measure the most abundant AP in PW. The advantages of biologically independent measures of exposure for inclusion in discharge monitoring studies are outlined. 相似文献
70.
Noble gases in 18 Martian meteorites and angrite Northwest Africa 7812—Exposure ages,trapped gases,and a re‐evaluation of the evidence for solar cosmic ray‐produced neon in shergottites and other achondrites
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R. Wieler L. Huber H. Busemann S. Seiler I. Leya C. Maden J. Masarik M. M. M. Meier K. Nagao R. Trappitsch A. J. Irving 《Meteoritics & planetary science》2016,51(2):407-428
We present noble gas data for 16 shergottites, 2 nakhlites (NWA 5790, NWA 10153), and 1 angrite (NWA 7812). Noble gas exposure ages of the shergottites fall in the 1–6 Ma range found in previous studies. Three depleted olivine‐phyric shergottites (Tissint, NWA 6162, NWA 7635) have exposure ages of ~1 Ma, in agreement with published data for similar specimens. The exposure age of NWA 10153 (~12.2 Ma) falls in the range of 9–13 Ma reported for other nakhlites. Our preferred age of ~7.3 Ma for NWA 5790 is lower than this range, and it is possible that NWA 5790 represents a distinct ejection event. A Tissint glass sample contains Xe from the Martian atmosphere. Several samples show a remarkably low (21Ne/22Ne)cos ratio < 0.80, as previously observed in a many shergottites and in various other rare achondrites. This was explained by solar cosmic ray‐produced Ne (SCR Ne) in addition to the commonly found galactic cosmic ray‐produced Ne, implying very low preatmospheric shielding and ablation loss. We revisit this by comparing measured (21Ne/22Ne)cos ratios with predictions by cosmogenic nuclide production models. Indeed, several shergottites, acalpulcoites/lodranites, angrites (including NWA 7812), and the Brachina‐like meteorite LEW 88763 likely contain SCR Ne, as previously postulated for many of them. The SCR contribution may influence the calculation of exposure ages. One likely reason that SCR nuclides are predominantly detected in meteorites from rare classes is because they usually are analyzed for cosmogenic nuclides even if they had a very small (preatmospheric) mass and hence low ablation loss. 相似文献